(CBS Seattle) — A new study from the University of Washington finds that the skinniest men in America live in San Francisco county. The Institute for Health Metrics and Evaluation (IHME) looked at the percentage of the male population considered obese, according to the International Science Times, and fewer than one in five men in the Golden Gate City fall into that category.

The second-trimmest city was New York, where just over 19 percent of men are obese. The New York Daily News speculates that the prevalence of Type-A personalities in bigger cities like San Francisco and New York could account for the more slender population. The paper also notes that men and women in these areas are typically better educated and wealthier, which correlates to a smaller waist size.

Falls Church City, Virginia and Pitkin, Colorado were the counties with the lowest obesity rates in women.

No Washington counties fell into either the highest or lowest percentages of obesity for men or women.

The IHME also found physical activity among adults increased between 2001 and 2009. Two Washington counties were among the most active in the country: Jefferson county for men and San Juan county for women.